KBS Modulation Depth on the Kasina

The Kasina has the ability to alter the modulation depth programmed in a KBS file from the interface. It can also apply volume modulation to external audio files played through the AUX jack. This post describes this feature which was introduced in firmware 1.12. It shows up in the KBS player.

Two settings work in conjunction with one another. The UP button on the Control Pad controls to what audio the modulation is applied. Either KBS audio only, AUX audio only or both KBS and AUX.

Mod KBS + AUX uses the Depth parameter in the KBS file and the MD setting to affect both the tones in the KBS file and an audio stream piped in the AUX jack.Mod KBS uses the Depth parameter in the KBS file and the MD setting to affect only the KBS tones in the session. Incoming audio will play without modulation.Mod AUX uses the Depth parameter in the KBS file and the MD setting to affect only incoming audio. The tones in the KBS session will be muted.

The second setting is accessed by the RIGHT button on the Control Pad. It determines if the depth of the modulation programmed in the KBS is altered or not. The options are:

In addition to modulating the tones in the KBS session, you can use the frequencies in the KBS session to increase and decrease the volume of an audio stream at brainwave rates.

This is enabled by Mod KBS + AUX or Mod AUX. The audio stream currently must come from the AUX jack, that is external audio from say a smartphone. The KBS session provides the instructions for the frequencies of this 'tremolo' effect. The Sound Depth parameter in the KBS segment controls how much the audio is chopped up.

In the normal setting, Mod KBS, the tones in a KBS session are modulated to create isochronic pulses. Most often this is full depth at 100%. All factory KBS sessions use this depth besides binaural beats.

For instance at 100% in the KBS segment, the tones in segment and/or the AUX audio stream will be go from full volume to zero volume at each pulse.

Let's say the frequency is 10hz, then it would do this 10 times per second. If the KBS segment had a depth setting of 50% then the audio volume and tone volume would go from 100% (full) to 50% (half), ten times per second. At this setting the modulation is more subtle and you would continue to hear much of the non-effected audio during the pulse.

A volume modulation of 100% is too much for most incoming audio unless it is something like an ambient drone. Rather than having to change the KBS session we introduced the MD (modulation depth) setting for KBS files in the Kasina interface.

The modulation depth setting - MD plus a percentage value - on the Kasina overrides or subtracts from the Sound Depth parameter in the KBS session. If the KBS segment had a depth setting of 100% then MD 100% would keep the volume modulation of the audio at 100% (multiplying 100 * 1). If the setting is MD 75% on the Kasina and Sound Depth 100% in the KBS segment then the final volume modulation value would be 75% (multiplying 100 * 0.75 = 75)

A quick table of examples:

KBS setting

MD setting

Result

100

100

100

100

75

75

100

50

50

100

25

25

50

100

50

25

100

25

50

50

25

50

75

37.5

50

25

12.5

0

100

0

The KBS Sound Depth parameter in the KBS file on the card will usually be set to 100% to generate isochronic pulses. That is, unless the segment uses binaural beats at which point the Sound Depth setting will be 0. For most sound files that you stream through the AUX jack you would like a subtle, but noticeable modulation. The useful settings for AUX audio are then either MD 50% or MD 25%.